Sheet metal structure especially adapted for airplane rudders



p 1933- E. J. w. RAGSDALE SHEET METAL STRUCTURE ESPECIALLY ADAPTED FOR AIRPLANE RUDDERS Filed June 23, 1951 1 N VENTOR.

FIG. 1

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Patented Sept. 19, 1933 smnrr METAL STRUCTURE nsrEcIALtY ADAPTED FOR AIRPLANE RUDDERS Earl J. W. Ragsdale, Norristown, Pa., assignor to Edward G. Budd Manufacturing Company,

rhiladelphia, Pa., a Vania corporation of Pennsyl- Application June 23, 1931. Serial No. 546,221

. 3 Claims.

My invention relates to composite sheet metal structures formed of relativelylight gauge sheet metal parts integrally joined together, preferably by spot welding. It has been my particular object to produce light and strong aerofoil framework members of such material. While the invention probably has many other applications, it has been evolved and is here illustrated in connection with the manufacture of an aerofoil in the nature of an airplane rudder.

Certain of the joints devised in the production of this structure have possibilities of application in other connections than the one hereillustrated and they are accordingly broadly claimed.

The manner in which I have attained the above and other objects of my invention will be apparent from a reading of the sub-joined specification in the light of the attached drawing, in which,

Fig. 1 is a side elevation of an airplane rudder illustrating the features of my invention;

Fig. 2 is an enlarged perspective view looking in the direction of the arrows 2--2' of Fig. 1, parts on the reverse side being omitted for the sake of clearness of illustration.

Fig. 3 is a detail view of one of the improved joints embodied in my rudder construction, and

Fig. 4 is another detail view of the same joint illustrated in Fig. 3, taken at right angles thereto.

Referring to the drawing by reference characters, the numeral 10 indicates the main spar of my aerofoil section which is connected to a marginal frame member 11 by means of suitable webbing 12. The main spar comprises a pair of opposed channel shaped side beams 13 interconnected by webbing 14. These side beams are bowed from end to end, the main spar being widest in its central portion. The webbing by which the main spar is interconnected with the marginal frame member consists in a plurality of vertical and diagonal ribs 15, each comprising chords 16 of channel section which telescope at their ends adjacent channel shaped marginal frame member 11 and are secured together through said telescoping portions; The chords 16 are interconnected by beams'18 in the form of flanged reinforcing plates secured to the side flanges of the channel shaped chord members.

The ribs are secured to a second spar 28 through a welded joinder of a flange on one of the beams 18 to flanges on said second spar. The flanged margins of the beams 13 constituting the side members of the main spar 10 are like-.

the main spar through a welded joinder with gusset plates 19 secured to the bases of the chords 16 of the ribs and likewise secured through a spot welded joinder to the main body portions of the beams 13 of the main spar. The ribs are 7 likewise secured to the marginal frame member 11 bylgusset plates 20.

In applications where a plurality of diagonal and vertical ribs meet in substantially the same region in the neighborhood of the marginal frame member, a common gusset plate may secure aplurality of these web members in place.

The marginal frame member .11 is secured to the main spar on opposite ends of said spar, as indicated at 21 and is continued downwardly beyond these zones of joinder with the main spar. As illustrated, this marginal frame member is brought into contact with the main spar, intermediate the ends thereof at 22 and secured thereto. At the opposite end of the aerofoil the extension of the marginal frame member is inter connected with the main spar by webbing 23 of a similar nature to the ribs previously described in connection with the securement of the principal portion of the marginal frame member to. the main spar. Additional struts 27 are con nected to the main spar through its central portion to form a reenforcing truss at this point.

I now wish to call especial attention to the nature of the joint 24 illustrated in the lower left hand side of Fig. 1 and in Fig. 2 of the drawing. This joint connects the marginal frame member 11 with a diagonal strut 29 and with a rib which ties both of these members to the main spar. It constitutes a cup shaped sheet-'- metal member receiving the extremities of all of these parts and welded to each of them. This cup shaped member may be formed in two parts 25, 26. Plate 25 is secured to the ends of the chords 16 at the lower extremity of the rib illustrated in Fig. 2; A curvilinear plate 26 is welded to the bases of the channels of these chords and is likewise welded to a portion of the marginal frame member 11 and to the diagonal strut 29. I have thus produced a simple and eifective joinder between all of these parts. 1

Modifications will be obvious to those skilled in the art and I do not therefore wish to be limited except by the scope of my sub-joined claims as interpreted in the light of the generic spirit of my invention. 1

What I claim is:

l. A rib for aerofoils including a pair of channel section chord members interconnected by op- 1 posed channel-shaped transversely extending reinforcing beams secured thereto through the bases of their channel sections.

2. Aerofoil structure including, in combination, a rib comprising channel section chord members and opposed transversely extending channelshaped reinforcing members connected to the chord members through the bases of the channel thereof, and a spar extending transversely of the rib members and secured thereto through the adjacent side walls of said channel-shaped reinforcing members. 

